Precast concrete beam element and methods of making and installing same

ABSTRACT

An improved precast concrete beam element, useful as a continuous bearing structural foundation member supporting wall and floor slab loads in soil, has a unique shape and includes a bearing surface for spreading vertical loads into the soil and a wall section having a height sufficient to place the bearing surface at a specified bearing depth in the soil. Optionally, the precast beam element also includes a formed-in notch to serve as a block ledge to facilitate weathertight wall installation. By integrating both the slab form edge and the wall ledge, the beam element eliminates the need for field forming. The beam element is manufactured offsite in a mold capable of changing dimension to cast elements with differing bearing heights and differing wall thicknesses as soil and loading conditions require. Installation of the beam element involves simple suspension of the beam element above an excavated trench such that a gap is formed between the bottom and sides of the trench and the surfaces of the beam element. As the beam element is suspended above the trench, a flowable fill material is poured into the trench to fill the gap. When the flowable fill material hardens, the beam element is locked into place, achieving full bearing and lateral stability.

[0001] This is a regular application based on U.S. ProvisionalApplication No. 60/175,428, which was filed on Jan. 11, 2000.

BACKGROUND OF THE INVENTION

[0002] This invention relates to a precast concrete structural elementand to methods of making and installing same. More particularly, thisinvention relates to a precast concrete beam element for providingcontinuous footing support in building and structure foundations and tomethods of making the precast element and installing it in building andstructure foundations.

[0003] Several methods for providing continuous beam footing for walland floor slab support in building and structural foundations are knownin the art. Three of the most popular methods are described below.

[0004] One popular method involves excavating a trench, placing edgeforms and reinforcement in the trench, and either partially casting thebeam and then casting the floor slab or simultaneously casting the beamand floor slab. This method has several disadvantages. For example, themethod requires an excavation that is open to weather conditions whilereinforcement is being placed in the trench. This often necessitatesremoval of the reinforcement after inclement weather has passed in orderto remove mud and water from the excavation and restore bearing capacityprior to casting. In addition, this method requires field forming of thefloor slab edge and the wall ledge. Thus, the accuracy of the slab edgeforming, the wall ledge forming and the beam shape are each dependent onthe skill of the craftsmen executing the work in the field. Furthermore,the method uses more concrete that would be required simply forstructural purposes in order to save the cost of forming a thinner wallthickness that is required structurally. This increase in sectional areaof the concrete necessitates an increase in the amount of steelreinforcement required under some building codes. Also, the increase inthe bearing width requires additional unnecessary concrete in the uppersection of the beam.

[0005] A second popular method for providing continuous beam footing tosupport wall and floor slab edges involves excavating a trench, castingthe continuous bearing beam in the trench, forming an upper stem wallsection including a support notch for a floor slab, casting the stemwall section, removing the forms, backfilling void areas adjacent to thestem wall, and then casting the floor slab.

[0006] This second method offers some advantages over the first methoddiscussed above in that, in the second method, the upper stem wall canbe formed to the minimum thickness required for structural needs,thereby saving substantial concrete material if the bearing depth issignificant. The second method also allows for a greater differencebetween finish floor height and the ultimate exterior grade. However,the second method also has several disadvantages. For example, itrequires an excavation open to weather conditions as in the first methodbut in the second method the excavation is open for an even longerperiod while the stem wall section is formed. The second method requireslabor-intensive forming of the stem wall section, often in below gradeconditions which may require continuous dewatering to achieve astructurally sound installation. The second method further requiressubsequent backfilling and compaction of the void areas adjacent to thestem wall. Moreover, the second method requires either a notch tosupport the floor slab or steel rods through the inner face form toprovide shear dowels into the floor slab. In addition, the accuracy ofthe slab edge forming, the slab bearing notch, and the stem wall sectionare each dependent on the skill of the craftsmen executing the work inthe field.

[0007] A third popular method for providing continuous beam footing tosupport wall and floor slab edges is similar to the second methoddiscussed above, except that in the third method, the exterior walls(usually masonry) are extended to the top of the bearing beam, followedby floor casting. In an advantage over the second method, the thirdmethod eliminates the stem wall forming step. However, the third methodrequires an extended period of open excavation and, typically, the timerequired for the installation of the below-grade portion of the exteriorwall is even longer than that required to form the stem wall in thesecond method. Furthermore, installation of the below-grade portion ofthe exterior wall is labor intensive. In a further disadvantage, thethird method requires backfilling and compaction of the void areasadjacent to the below-grade portion of the exterior wall. In addition,accuracy is still dependent upon the skill of the craftsmen executingthe work in the field.

[0008] A primary object of this invention is to provide an improvedconcrete beam element which integrates the edge of slab form and thewall ledge to completely eliminate the need for field forming.

[0009] Another object of this invention is to provide an improvedconcrete beam element which is capable of being cast with dowel rodsprojecting above the wet concrete instead of through the mold.

[0010] A further object of this invention is to provide an improvedmethod of making a concrete beam element which does not require fieldforming.

[0011] A still further object of this invention is to provide animproved method of making a concrete beam element wherein the methoduses a mold that allows for varying beam heights to accommodate varyingbeam depths.

[0012] Another object of this invention is to provide an improved methodof making a concrete beam element wherein the method uses a mold thedepth of which can be easily increased to offer additional bearingcapacity or stem wall thickness as soil and loading conditions require.

[0013] Yet another object of this invention is to provide an improvedmethod of installing a concrete beam element wherein the exposure periodof the excavation site to the weather is significantly less than thatrequired in the prior art methods discussed hereinabove.

[0014] These objects and others are achieved in the present invention.

SUMMARY OF THE INVENTION

[0015] The present invention provides an improved precast concrete beamelement for use as a continuous bearing structural foundation membersupporting wall and floor slab loads in soil. The present inventionfurther provides an improved method of making the aforementioned precaststructural beam element. In addition, the present invention provides animproved method for installing the precast concrete beam element of thisinvention into a building or structural foundation.

[0016] Specifically, the precast structural beam element of thisinvention has:

[0017] (i) a straight back face;

[0018] (ii) a top surface;

[0019] (iii) a bottom surface;

[0020] (iv) a front face; the front face having:

[0021] a first upper surface extending perpendicularly and downwardlyfrom the top surface and being parallel to the back face;

[0022] a second upper surface which slopes downwardly and inwardly fromthe first upper surface;

[0023] a middle surface which is parallel to the back face and whichextends downwardly from the second upper surface;

[0024] a first lower surface which slopes downwardly and outwardly fromthe middle surface; and

[0025] a second lower surface which is parallel to the back face andwhich extends downwardly from the first lower surface andperpendicularly to the bottom surface; and

[0026] (v) first and second opposite side faces disposed between theback and front faces and between the top and bottom surfaces.

[0027] Preferably, the beam element of this invention will have a notchformed therein which extends lengthwise along the top surface and/or themiddle surface of the front face has a dapped surface formed therein.

[0028] The method of making the beam element involves the steps of:

[0029] (1) providing a mold containing:

[0030] (a) a longitudinally movable lateral side rail having an innerwall for forming the top surface of the beam element;

[0031] (b) an opposite fixed lateral side rail having an inner wall forforming the bottom surface of the beam element;

[0032] (c) a first longitudinal side rail disposed between the movableand fixed lateral side rails and having an inner wall for forming thefirst side face of the beam element;

[0033] (d) an opposite second longitudinal side rail disposed betweenthe movable and fixed lateral side rails and having an inner wall forforming the second side face of the beam element;

[0034] (e) an infill plate disposed between the inner walls of thelateral and longitudinal side rails such that an upper face of theinfill plate and the inner walls of the lateral and longitudinal siderails define a mold cavity, the upper face of the infill plate beingdisposed to form the front face of the beam element; and

[0035] (f) one or more dowel rods projecting upwardly from the moldcavity;

[0036] (2) filling the mold cavity with a flowable fill material;

[0037] (3) allowing the flowable fill material to harden to form thebeam element; and

[0038] (4) removing the beam element from the mold cavity.

[0039] The method of installing the beam element of this inventioninvolves the steps of:

[0040] (1) providing an excavated trench having a bottom surface, innerwall surfaces and an open top surface;

[0041] (2) suspending the beam element above the trench so that a bottomgap is formed between the bottom face of the beam element and the bottomsurface of the trench and a side gap is formed between the inner wallsof the trench and the front, back and side faces of the beam element;

[0042] (3) pouring a flowable fill material into the trench so as tofill the bottom gap and at least a portion of the side gap; and

[0043] (4) causing the poured material to harden.

[0044] The present invention further provides a method for forming afloor slab, involving the steps of:

[0045] (1) installing the beam element of this invention in accordancewith the method of this invention;

[0046] (2) providing a floor slab-forming location for forming the floorslab, the location being adjacent to the beam element such that the backface of the beam element will serve as an edge form during casting ofthe floor slab; and

[0047] (3) casting the floor slab in the location.

[0048] In addition, the present invention provides a method of forming awall slab, involving the steps of:

[0049] (1) installing the beam element of this invention in accordancewith the method of this invention;

[0050] (2) providing a wall slab-forming location for forming the wallslab, the location being adjacent to the beam element such that the topface of the beam element will serve as an edge form during casting ofthe wall slab; and

[0051] (3) casting the wall slab in the location.

[0052] The precast concrete beam element of this invention has a uniqueshape and includes a bearing surface (defined by the bottom surface ofthe beam element) for spreading vertical loads into soil and a wallsection (defined by the back face of the beam element) having a heightsufficient to place the bearing surface at a specified bearing depth inthe soil. Optionally, the precast beam element also includes a formed-innotch to serve as a block ledge to facilitate weathertight wallinstallation. The beam element of this invention integrates both theslab form edge and the wall ledge, thereby eliminating the need forfield forming.

[0053] The precast concrete beam element of this invention ismanufactured offsite in a mold capable of changing dimension to castelements with differing bearing heights. The unique shape of the beamelement allows it to be cast with dowel rods projecting above the wetconcrete instead of through the mold. In addition to offering adjustablebeam height for varying beam depths, the mold depth can be easilyincreased to offer additional bearing capacity or stem wall thickness assoil and loading conditions require.

[0054] The method of installing the precast concrete beam element ofthis invention involves the simple suspension of the beam element abovean excavated trench with a gap being formed between the bottom and sidesof the trench and the surfaces of the beam element. As the beam elementis suspended above the trench, a flowable fill material is poured intothe trench to fill the void areas. When the flowable fill materialhardens, the beam element is locked into place, achieving full bearingand lateral stability.

[0055] The present invention offers many advantages over the prior art,as discussed below.

[0056] For example, the beam element of the present invention is madeusing an adjustable mold which provides the ability to manufacture beamelements with varying structural capacities.

[0057] In addition, the particular cross-section of the beam element ofthis invention provides structural capacity with minimal material andweight. Furthermore, such cross-section also allows for efficientstacking of the beam elements in the storage yard and facilitates easyhandling for loading and trucking.

[0058] Another advantage is that the beam element of this invention iscapable of serving as a stay-in-place form for the slab edge and thewall ledge.

[0059] Another advantage of the present invention is that theconstruction site can be prepared while the beam elements are beingproduced offsite. This facilitates rapid installation of the elements assoon as the site preparation is complete.

[0060] Furthermore, in the present invention, the flowable fill materialis cast as the beam elements are being installed, thereby greatlyreducing the exposure time of the excavation site to inclement weather.

[0061] No edge forming of the slab, wall ledge or field forming of thestem wall is required in the method of making the beam element of thepresent invention.

[0062] Installation accuracy is assured in the present invention sincethe installation workmen can adjust the beam location using anadjustable hanger. The beam element is grouted and secured into placebefore the slab is cast, thereby assuring that the edge will not vary asfield forms tend to do under the pressure of concrete casting.

[0063] Another advantage offered by the present invention is that theuse of special forms to make the beam elements eliminates dependency onskilled labor to assure accurate beam and slab edge dimensions.

BRIEF DESCRIPTION OF THE DRAWINGS

[0064]FIG. 1 is a schematic illustration of a longitudinal side view ofa mold which can be used to form the beam element of this invention.

[0065]FIG. 2 is a schematic illustration of a perspective view of themold shown in FIG. 1.

[0066]FIG. 3 is a schematic illustration of the mold shown in FIG. 1,wherein the mold is filled with concrete.

[0067]FIG. 4 is a schematic illustration of a beam element of thisinvention formed from the mold shown in FIGS. 1-3, wherein the beamelement is being removed from the mold.

[0068]FIG. 5 is a schematic illustration of a stack of the inventionbeam elements for storage and shipping.

[0069]FIG. 6 is a schematic illustration of a beam element of thepresent invention being suspended over a trench in accordance with theinstallation method of this invention.

[0070]FIG. 7 is a schematic illustration of the grouting step of theinstallation method of this invention using the beam element and trenchshown in FIG. 6.

[0071]FIG. 8 is a schematic illustration of the slab-pouring step of theinstallation method of this invention, using the beam element, trenchand grouting material shown in FIG. 7.

[0072]FIG. 9 is a schematic illustration of the installed beam elementof this invention prior to removal of the suspension equipment.

DETAILED DESCRIPTION OF THE INVENTION

[0073] The precast concrete beam element of this invention, its methodof manufacture and its method of installation will be described withreference to FIGS. 1-9 herein.

[0074] The precast concrete beam element of this invention ismanufactured in a mold capable of changing dimension to cast elementswith differing bearing depths and structural capacities. Such a mold isrepresented by reference numeral 2 in FIGS. 1-4.

[0075] Mold 2 includes a movable lateral side rail 4, a fixed lateralside rail 6, and first and second longitudinal side rails (not shown).Movable lateral side rail 4 has an inner wall 4 a, an upper portion ofwhich preferably contains a notch 4 b. Notch 4 b is used to form a notch36 in the concrete beam element (see FIGS. 4-9). Fixed lateral side rail6 has an inner wall 6 a. A channel 8 is defined between the inner walls4 a, 6 a of the lateral side rails, the inner walls (not shown) of thelongitudinal side rails and the upper face of a support member 10.

[0076] Movable lateral side rail 4 rests on a movable side rail basemember 12 which in turn rests on support member 10. Fixed lateral siderail 6 also rests on support member 10.

[0077] Side rail base member 12 is longitudinally movable in thedirection shown. In the embodiment shown in FIG. 2, side rail basemember 12 and support member 10 each contain through-holes (not shown)and are attached to one another at a contact point 14 by aligning therespective through-holes in the base member and the support member andthen placing screws 16 placed in the through-holes. In such embodiment,the base member 12 can be moved by removing the screws and moving thebase member to a second contact point (not shown) located either onsupport member 10 or on a subsequent support member (not shown). At thesecond contact point, the support member will contain through-holes (notshown), which are aligned with the through-holes disposed in the siderail base member. Screws 16 are then placed through the alignedthrough-holes, thereby securing the side rail base member 12 to thesupport member at a second contact point.

[0078] Mold 2 preferably further includes a number of support blocks 18preferably one support block every four feet), preferably made of wood,which is placed in channel 8. Blocks 18 inturn each preferably rest on asecond support block 20. An infill plate 22 (preferably made of steel),the upper face of which defines the front face of the beam element to beformed, is placed in channel 8 over support blocks 18. The upper face 22a of plate 22, inner walls 4 a, 6 a of the lateral rails 4, 6, and theinner walls (not shown) of the longitudinal side rails define a moldcavity 24. Upper face 22 a of plate 22 forms the front face of the beamelement to be formed, the inner wall 4 a of side rail 4 forms the topface of the beam element, the inner wall 6 a of side rail 6 forms thebottom surface of the beam element, and the tipper edge of mold cavity24 forms the straight back face of the beam element. The inner walls ofthe longitudinal side rails (not shown) form the side faces of the beamelement.

[0079] The height of the beam element to be formed can be increased bymoving side rail 4, via side rail base member 12, longitudinally in thedirection shown, as discussed hereinabove.

[0080] Projecting within and vertically upwardly from mold cavity 24 areone or more dowel rods 26. Dowel rod(s) has an upstanding portion 26 aand an embedded portion 26 b which is embedded in the concrete beamelement to be formed.

[0081]FIG. 3 shows mold cavity 24 filled with concrete C to effectcasting of the beam element of this invention. An advantage of thepresent invention is that the dowel rod(s) 26 is positioned in the moldcavity when the wet concrete is poured therein. Thus, the dowel rodportion 26 a projects above the wet concrete instead of through themold. This allows steel rods to project above the surface of the formedconcrete beam element to dowel into the floor slab without requiring apenetration of the mold.

[0082] After the concrete C has hardened in mold cavity 24, theresulting beam element 28 is removed from mold 2. As shown in FIG. 4,the beam element 28 can be removed from the mold by pivoting lateralside rails 4 and 6 outwardly (in the direction of the arrows shown inFIG. 2) until the rails rest on rail-stopping members 30 and 32,respectively, and by pivoting longitudinal side rails (not shown) in thesame manner.

[0083] As can be seen in FIG. 4, dowel rod portion 26 a protrudesupwardly from the formed beam element 28.

[0084] During storage and shipping, a plurality of beam elements 28 canbe stacked as shown in FIG. 5, with spacers 34 disposed between adjacentbeam elements.

[0085] The beam element of this invention preferably has the shape shownin FIGS. 4-9 herein.

[0086] As shown in FIGS. 4-9, beam element 28 includes a straight backface 28 a, a top surface 28 b, a bottom surface 28 c, a shaped frontface defined by surfaces 28 d, 28 e, 28 f, 28 g and 28 h, and side faces28 i. Back face 28 a and side faces 28 i are designed to extendvertically relative to the ground G when the beam element is installed.Top surface 28 b is straight except for a notch 36 preferably formedtherein which extends lengthwise along top surface 28 b (see FIG. 9).Notch 36 serves as a block ledge during the casting of the floor slaband can facilitate weathertight wall installation. Top surface 28 b isintended to extend horizontally relative to the ground G when the beamelement is installed. Bottom surface 28 c is also straight and isdesigned to extend horizontally relative to the ground G when the beamelement is installed.

[0087] Beam element 28 is composed of (i) a first or upper flangedefined by an upper portion of back face 28 a, top surface 28 b,front-face surfaces 28 d and 28 e; and upper portions of side faces 28i; (ii) a middle section defined by a middle portion of back face 28 a,front-face surface 28 f and dapped surface 38 (see FIG. 9) and middleportions of the side faces 28 i; and (iii) a second or lower flangedefined by a lower portion of back face 28 a, front-face surfaces 28 gand 28 h, bottom face 28 c, and lower portions of side faces 28 i.Surface 28 d of the upper flange is straight and parallel to the backface 28 a of the beam element. Surface 28 e of the upper flange slopesinwardly and downwardly from surface 28 d toward the middle of the beamelement. Surface 28 f is straight and parallel to back face 28 a of thebeam element. Surface 28 g of the lower flange extends outwardly anddownwardly from surface 28 f. Surface 28 h of the lower flange isstraight and parallel to back face 28 a of the beam element. Dappedsurface 38, which has a Z shape, is used to align the plurality of beamelements during installation.

[0088] Installation of the beam elements of this invention can beunderstood by reference to FIGS. 6-9.

[0089] As shown in FIG. 6, precast beam element 28 is suspended above anexcavated trench 40 having a bottom surface 40 a and side walls 40 b.The beam element is suspended above trench 40 in such a way as to leavea gap or void area 42 a between the bottom face of the beam element andthe bottom surface of the trench; and a gap or void area 42 b betweenthe front, back and side faces of the beam element and the inner wallsof trench 40. The particular depth and width of the trench will varyaccording to the structural requirements for individual buildings andfoundation conditions.

[0090] Beam element 28 is suspended by bearing the first or upper flange(defined by surfaces 28 b, 28 d and 28 e and a portion of back face 28a) of the beam element on the dapped end (not shown) of a previouslyinstalled beam element (not shown), thereby aligning beam element 28with the previous beam element. The second or lower flange (defined bysurfaces 28 g, 28 h, 28 c and a portion of back face 28 a) of beamelement 28 is supported by a special adjustable suspension hanger 44that is fully adjustable in the directions shown (i.e., vertically andhorizontally) and torsionally. First and second end members 44 a and 44b of the hanger rest on the ground G as shown in FIG. 6.

[0091] As can be seen in FIG. 7, as beam element 28 is suspended abovetrench 40, a flowable fill material 46 (e.g., grout or wet concrete) ispoured into the trench to fill gap 42 a and at least a portion of gap 42b. As used herein, the term “pouring” is intended to include a pumpingoperation.

[0092] When material 46 hardens, the beam element 28 is locked intoplace, achieving full bearing and lateral stability. To reduce therequired flowable fill volume to the minimum required for structuralsupport, the remainder of gap 42 b can be filled with inexpensivegranular fill 48 (e.g., sand) and backfilled soil 50, as shown in FIG.8.

[0093] Since the flowable fill material 46 is capable of transferringload in a diagonal shear cone, the effective bearing area can be thefill width of trench 40 if the portion of gap 42 a below the bottom face28 c of beam element 28 is equal to the portion of gap 42 b between thetrench inner walls 40 b and the front, back and side surfaces of beamelement 28. By increasing the depth and width of the trench, the bearingarea can effectively be increased without enlarging the beam element. Asdiscussed hereinabove, the beam element of this invention can also beexpanded in width, stem wall thickness and depth so that a wide varietyof loading and soil conditions can be accommodated.

[0094] After beam element 28 has been secured into place, a floor slab52 can be cast, as shown in FIG. 8. During casting of the slab, the beamelement will not vary as field forms tend to do under the pressure ofconcrete casting. Thus, beam element 28 can serve as a stay-in-placeedge form during formation of the cast-in-place floor slab 52.

[0095] As stated previously herein, in preferred embodiments, beamelement 28 further has disposed therein a notch 38 (FIG. 9) extendingalong the length of the beam element. Notch 38 can serve as a block edgeto facilitate weathertight installation of a wall slab 54.

[0096] The precast concrete beam element of this invention can be madedirectly at the construction site by using a portable, ready-mix bulkplant. However, it is preferred to precast the beam elements at a remotefabrication location dedicated to that purpose and then transported tothe construction site.

What is claimed is:
 1. A precast structural beam element, comprising: (i) a straight back face; (ii) a top surface; (iii) a bottom surface; (iv) a front face; the front face having: a first upper surface extending perpendicularly and downwardly from the top surface and being parallel to the back face; a second upper surface which slopes downwardly and inwardly from the first upper surface; a middle surface which is parallel to the back face and which extends downwardly from the second upper surface; a first lower surface which slopes downwardly and outwardly from the middle surface; and a second lower surface which is parallel to the back face and which extends downwardly from the first lower surface and perpendicularly to the bottom surface; and (v) first and second opposite side faces disposed between the back and front faces and between the top and bottom surfaces.
 2. A beam element according to claim 1, wherein the top surface of the beam element has a notch formed therein which extends lengthwise along the top surface and/or the middle surface of the front face has a dapped surface formed therein.
 3. A method of making the beam element of claim 1, comprising the steps of: (1) providing a mold comprising: (a) a longitudinally movable lateral side rail having an inner wall for forming the top surface of the beam element; (b) an opposite fixed lateral side rail having an inner wall for forming the bottom surface of the beam element; (c) a first longitudinal side rail disposed between the movable and fixed lateral side rails and having an inner wall for forming the first side face of the beam element; (d) an opposite second longitudinal side rail disposed between the movable and fixed lateral side rails and having an inner wall for forming the second side face of the beam element; (e) an infill plate disposed between the inner walls of the lateral and longitudinal side rails such that an upper face of the infill plate and the inner walls of the lateral and longitudinal side rails define a mold cavity, the upper face of the infill plate being disposed to form the front face of the beam element; and (f) one or more dowel rods projecting upwardly from the mold cavity; (2) filling the mold cavity with a flowable fill material; (3) allowing the flowable fill material to harden to form the beam element; and (4) removing the beam element from the mold cavity.
 4. A method according to claim 3, wherein the inner surface of the longitudinally movable lateral side rail has a configuration so as to form a notch which extends lengthwise along the top surface, and/or the upper face of the infill plate has a configuration so as to form a dapped surface in the middle surface of the front face.
 5. A method according to claim 3, wherein the flowable fill material is concrete.
 6. A method for installing the beam element of claim I into the ground, comprising the steps of: (1) providing an excavated trench having a bottom surface, inner wall surfaces and an open top surface; (2) suspending the beam element above the trench so that a bottom gap is formed between the bottom face of the beam element and the bottom surface of the trench and a side gap is formed between the inner walls of the trench and the front, back and side faces of the beam element; (3) pouring a flowable fill material into the trench so as to fill the bottom gap and at least a portion of the side gap; and (4) causing the poured material to harden.
 7. A method according to claim 6, wherein the flowable fill material is concrete or grout.
 8. A method according to claim 6, wherein the top surface of the beam element has a notch formed therein which extends lengthwise along the top surface and/or the middle surface of the front face has a dapped surface formed therein.
 9. A method according to claim 6, further comprising after step (4), the step (5) of installing a second beam element of claim 1 in accordance with the method of claim 6, the second beam element being installed adjacent to the beam element installed according to the method of claim
 6. 10. A method for forming a floor slab, comprising the steps of: (1) installing the beam element of claim 1 in accordance with the method of claim 6; (2) providing a floor slab-forming location for forming the floor slab, the location being adjacent to the beam element such that the back face of the beam element will serve as an edge form during casting of the floor slab; and (3) casting the floor slab in said location.
 11. A method according to claim 10, wherein, in the beam element used in step (1), the top surface of the beam element has a notch formed therein which extends lengthwise along the top surface and/or the middle surface of the front face has a dapped surface formed therein.
 12. A method of forming a wall slab, comprising the steps: (1) installing the beam element of claim 1 in accordance with the method of claim 6; (2) providing a wall slab-forming location for forming the wall slab, the location being adjacent to the beam element such that the top face of the beam element will serve as an edge form during casting of the wall slab; and (3) casting the wall slab in said location.
 13. A method according to claim 12, wherein, in the beam element used in step (1), the top surface of the beam element has a notch formed therein which extends lengthwise along the top surface and/or the middle surface of the front face has a dapped surface formed therein. 